Artificial tooth



ARTIFIC|AL H.

Patented June 1, 19 20 SAMUEL mm, or WALLASEY, nnGLANn.

1 ARTIFICIAL TOOTH.

Specification of Letters Patent.

. Patented June 1, 1920.

Application at September 20, 1917. Serial No. 192,370.

To all whom it may concern:

Be it known that I SAMUEL EARP, a subject of the King of (irreatBritain, residing at Wallasey, in the county of Chester, in the Kingdomof England, have invented certain new and useful Improvements in orBelating to Artificial Teeth, of which the following is a specification.

This invention relates to improvements in artificial teeth intended tobe used in combination with plates of vulcanite or the like and moreparticularly to what may be termed full contour all-porcelain toothcrowns.

According to the invention, the tooth has a hollow tapering outward fromwithin the incisal edge to its base to receive the filling of vulcaniteor the like in which is embedded a post secured to the tooth at the apexof the said hollow in the incisal edge or tip and extending the fulldepth of said tooth.

The post of suitable metal is secured to the porcelain tooth either bybeing fired in or soldered to a tube of platinum or the like preferablysplit, which has been previously 1 fired in the crown, or again the postmay be fixed by means of Brills cement or other suitable known materialcapable of withstanding the conditions of the vulcanlzing process.

It is preferable to use a post flattened at the sides and this post maybe of any usual form, splayed, headed, hooked or provided withprojections to give a greater surface of engagement for the vulcanite.

The invention is more particularly described with reference to theaccompanying drawings, in which Figure 1 is a side sectional elevationthrough the tooth,

Fig. 2 is a corresponding front sectional elevation,

Fig. 3 is a side sectional elevation of a modification,

Fig. 4 is a view of acapsule for assistingvin the securing of the post,

ig. 5 is an alternate form of capsule.

Fig. 6 is a sectional plan view of a narrow tooth,

Fig. 7 is a corresponding sectional elevation.

The porcelain tooth A has a hollow cavity tapering outward formed in itextending from its base right up toward the incisal edge in which isfirmly anchored the post B to'be surrounded by a filling of vulcanite Cwhich will consequently also be tapering in form. The post B may betapered at its lower end or may be headed as shown, in which case it isusually desirable to arrange it at an angle so as to give as much roomas possible under the tooth, which is particularly suitablewhere it isdesired to insert a metal strengthener in the base plate.

A spiral groove or serrations E may be formed on the interior surface toprovide a greater gripping surface for the vulcanite.

At the point where the post B is'fizged to the tooth A the vulcanitewill become very thin and at this point of possible weakness astrengthener in the form of a metal capsule can be inserted. Thiscapsule may be in the form of a narrow ring as shown in Fig. 4 or mayextend the whole distance of the interior of the cavity as shown inFigs. 3 and 5. The capsule F mayi if desired, be provided with a spiralrib adapted to engage a corresponding groove on the interior surface ofthe porcelain.

The post B is provided with a number of projecting or abutment surfacesG to prevent the tooth from being pulled off the said post.

If desired, as shown in Figs. 6 and 7,.

the tooth A can be provided at its sides with g a thickening I over atriangular area, which will'still preserve the natural contour inappearance when the tooth is mounted. This arrangement is particularlysuitable for narrow teeth such as lower central'incisors and upperlateral incisors.

To reduce the possibility of breakage under flask press power and due tothe expansion of the rubber during vulcanizing,

relief passages D opening to the sides or base of the teeth may beprovided. The conical form of cavity in itself forming, of course, themain means for relief.

One or more metal pins, tags or flanges of usual form can be arranged onthe in-- terior surface of the porcelain for the purpose of holding thetooth more securely to the vulcanite.

I declare that what I claim is .1. As an article of manufacture, a fullcontour porcelain crown artificial tooth having a conical cavityextending from its base to its incisal edge, a post in said cavitysecured directly to the tooth in its incisal edge, a conical metalsleeve at the integral junction of the post with the incisal edge 'Qemme of the tooth, and a filling of vulcanite of truncated conicalinternal and external form filling the remainder of said cavity.

2. As an article of manufacture, a full 5 contour porcelain crownartificial tooth, having -a conical cavity extending from its base toits incisal edge, a post insaid cavity secured directly to the tooth inits incisal edge, abutment flanges on said post facing 10 the tip of thetooth, and a filling of vulcanite of truncated conical internal andexternal form filling the remainder of said cavity.

In Witness whereof I have hereunto signed my name this 28th day ofAugust, 1917 in the presence of two subscribing 15 Witnesses.

SAMUEL ARP, Witnesses:

ARTHUR ARMSTRONG, JOHN MCLAOHLAN.

